Mitsubishi 380. Manual - part 193

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-68

SYMPTOM CHART

M1552009900495

CAUTION

During diagnosis, a DTC code associated with
other system may be set when the ignition switch
is turned on with connector(s) disconnected. On
completion, confirm all systems for DTC code(s).
If DTC code(s) are set, erase them all.

SYMPTOM

INSPECTION
PROCEDURE

REFERENCE
PAGE

When the ignition switch is "ON", the A/C does not operate.

P.55-69

When the air outlet changeover control knob is moved to DEFROSTER or
DEFROSTER/FOOT position, the A/C or the inside/outside air
changeover damper motor does not operate.

P.55-69

Outside/Inside air changeover is not possible.

P.55-70

When the A/C is operating, temperature inside the passenger
compartment does not decrease (cool air is not emitted).

P.55-75

Blower fan and motor do not turn.

P.55-89

Blower air amount cannot be changed.

P.55-100

The A/C indicator flashes.

P.55-104

Defogger function does not operate.

P.55-110

Defogger timer function does not operate.

P.55-121

Malfunction of the A/C-ECU power supply system.

10.

P.55-122

Condenser fan does not operate.

11.

REFER TO
GROUP 14

−

SYMPTOM
CHART

P.14-3

When sunlight intensity changes, air outlet temperature does not change. 12

P.55-128

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-69

SYMPTOM PROCEDURES

INSPECTION PROCEDURE 1: When the Ignition Switch is "ON", the A/C does not Operate.

TECHNICAL DESCRIPTION (COMMENT)

The blower system or the compressor system may
be defective if there is no cool air coming from the
vents.

TROUBLESHOOTING HINTS

• Malfunction of blower motor

• Malfunction of A/C compressor

• Refer to component locations GROUP-

• Refer to configuration diagrams GROUP-

• Refer to circuit diagrams GROUP-

DIAGNOSIS

Check that the blower motor operation when the blower
switch is moved to the "HI" position.
(1) Turn the ignition switch to the "ON" position.
(2) Turn the blower speed selection dial to the blower operating

position.

Q: Does the blower motor operate when the speed

selection dial is turned to the blower operating
position?
YES : Refer to Inspection procedure 4 "When the A/C is

operating, temperature inside the passenger
compartment does not decrease (cool air not emitted)

P.55-75

NO : Refer to Inspection procedure 5 "Blower fan and

motor do not turn

P.55-89

INSPECTION PROCEDURE 2: When the Air Outlet Changeover Control Knob is Moved to
DEFROSTER or DEFROSTER/FOOT Position, the A/C or the Inside/outside Air Changeover Damper
Motor does not operate.

TECHNICAL DESCRIPTION (COMMENT)

If the outside/inside air selection damper control
motor does not operate normally, the inside/outside
air changeover damper motor system may be defec-
tive.

TROUBLESHOOTING HINTS

• Malfunction of the A/C-ECU

• Malfunction of the outside/inside air selection

damper control motor

• Damaged harness wires or connectors

• Refer to component locations GROUP-

• Refer to configuration diagrams GROUP-

• Refer to circuit diagrams GROUP-

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-70

DIAGNOSIS

Check operation of the outside/inside air selection damper
control motor.
(1) Turn the ignition switch to the "ON" position.
(2) Outside/inside air selection damper motor switch: This is

used to switch from the inside air to outside air or vice
versa.

(3) Check to see that the outside/inside air selection damper

motor operates normally.

Q: Does outside/inside air selection damper control motor

work normally?
YES : Replace the A/C-ECU.
NO : Refer to Inspection procedure 3, "Inside/outside air

changeover is not possible

P.55-70

INSPECTION PROCEDURE 3: Outside/Inside Air Changeover is not possible.

CIRCUIT OPERATION

If the outside/inside air selection damper control
motor does not operate normally, the outside/inside
air selection damper control motor system may be
defective.

TROUBLESHOOTING HINTS

• Malfunction of the outside/inside air selection

damper control motor

• Malfunction of the A/C-ECU

• Damaged harness wires or connectors

• Refer to component locations GROUP-

• Refer to configuration diagrams GROUP-

• Refer to circuit diagrams GROUP-

DIAGNOSIS

Required Special Tool:

• MB991223: Test Harness Set

STEP 1. Check the defogger and A/C operations.

Q: Do the defogger and A/C work normally?

YES : Go to Step 2.
NO : Refer to Inspection procedure 10 "Malfunction of the

A/C-ECU power supply system

P.55-122

25DB093A

CONNECTORS: C-15, C-106

C-15 (B)

C-106

25DB094A

CONNECTORS: C-211, C-215

JUNCTION BLOCK

(FRONT VIEW)

C-215

C-211

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-71

STEP 2. Check outside/inside air selection damper control
motor connector C-106 for loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Q: Is outside/inside air selection damper control motor

connector C-106 in good condition?
YES : Go to Step 3.
NO : Repair or replace the connector. Refer to GROUP

00E, Harness Connector Inspection

P.00E-2

. Check

that the outside/inside air selection damper control
motor works normally.

STEP 3. Measure the voltage at outside/inside air selection
damper control motor connector C-106.
(1) Disconnect outside/inside air selection damper control

motor connector C-106, and measure the voltage at the
harness side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal 1 and ground.

• The measured value should be approximately 12 volts

(battery positive voltage).

Q: Does the measured voltage correspond with this range?

YES : Go to Step 5.
NO : Go to Step 4.

STEP 4. Check the wiring harness between outside/inside
air selection damper control motor connector C-106
(terminal 1) and the ignition switch (IG2).

25DB095A

HARNESS SIDE

CONNECTOR: C-106

25DB095A

HARNESS SIDE

CONNECTOR: C-106

AC209365

CONNECTOR C-106
(HARNESS SIDE)

25DB095A

HARNESS SIDE

CONNECTOR: C-106

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